Zeraora @ Leftovers / Heavy-Duty Boots
Ability: Volt Absorb
EVs: 12 HP / 244 Atk / 252 Spe
- Plasma Fists
- Knock Off
- Close Combat
- Bulk Up / Toxic
- naturally outspeeds without needing Choice Scarf
- supereffective Knock Off
- can take a Specs-boosted Shadow Ball in a pinch
As the only Pokémon that naturally outspeeds it, Zeraora is a premier check to Dragapult in SS OU thanks to its access to Knock Off.
244 Atk Zeraora Knock Off (97.5 BP) vs. 0 HP / 4 Def Dragapult: 238-282 (75 - 88.9%) -- guaranteed 2HKO
As you can see it doesn't OHKO, but Choice Specs Dragapult may take chip damage from Stealth Rock and potentially Rocky Helmet on predicted U-turn and thus can be brought into KO range. Furthermore, Knock Off is unique because it forces out Dragapult anyway due to the threat of removing Choice Specs, which makes it possible for Zeraora to survive a Draco Meteor and two Shadow Balls. Knock Off is also a very easy and safe move to click anyway, so even if you don't catch Dragapult you'll get value out of that turn for sure.
These forced switches can be taken advantage off by a timely Bulk Up or Toxic to end the match on the spot or make progress on the opponent's team, respectively. Speaking of Bulk Up, at +1 obviously Zeraora gains the power to easily OHKO Dragapult.